Dentist apparatus



Oct. 19, 1937. w, JONES 2,096,375

DENTIST APPARATUS Filed May 19, 1936 INVENTOR. WZZZWJE. J BY ATTORNEY.

Patented Oct. 19, 1937 UNITED STATES PATENT iQEE 1 Claim.

This invention relatesto improvements in dentists apparatus and isdirected more particularly to improvements in apparatus for use bydentists in the manufacture of false teeth and the like. It is one ofthe principal objects of the invention to provide a novel device wherebyan accurate impression of the patients upper jaw may be readily takenwithout the unpleasantness and difiiculty usually present during suchoperations. Not only does this device make the operation easier andpleasanter for the patient but it does not tend to detract from theefiiciency of the dentist.

It is another object of the invention to provide an improved so-calledimpression tray which is arranged to receive the plastic material fromwhich the impressions are commonly made and means is provided tofacilitate the dentists determining in advance the amount of plasticmaterial which will be needed to form the desired impression. That is tosay, the impression tray is so formed that it may be placed into thepatients mouth devoid of the impression-making material and prior to theactual impression-taking step and, by reason of the character of thedevice, it is possible for the dentist to then determine just howmuchplastic material he will need to place in the tray.

It is one of the distinctive features of the device of the inventionthat excess plastic material may be conveniently taken care of and theusual danger of its overflowing or dropping into the mouth of thepatient, and thus causing discomfiture and gagging and the like, isobviated.

Various other objects and advantages of the invention will become moreapparent after a reading of the following description of the presentpreferred form thereof and reference will be had tothe accompanyingdrawing wherein:

Fig. 1 is a plan. view of the device of the invention;

Fig. 2 is a sectional view on the line 2--2 of Fi 1;

Fig. 3 is a sectional view on the line 33 of Fig. 1;

Fig. 4 is a sectional view on the line 44 of Fig. 1; and

Fig. 5 is a sectional view similar to Fig. 2 showing the parts indifferent relation.

Referring now tothe drawing more in detail, the invention will be fullydescribed.

It is customary for the dentist, when making an impression of a patientsupper jaw to place in what is called an impression tray a certain amountof an impression-taking material, such as plaster of Paris, wax, or thelike, and then (in case of making the upper plate) to press this trayand its contents upwardly against the upper "jaw so that the jawdisplaces some of the plastic material. It is obvious that the displacedmaterial must go either towards the center of the tray or overflow theouter sides thereof.

Too much plastic at the center of course causes discomfort andundesirable pressure against the roof of the mouth while when thematerial overflows the sides of the tray it drops down into the mouth ofthe patient and causes gagging.

According to my invention, it is possible for the dentist to overcomethese difficulties.

Furthermore, it is diflicult for even the most experienced dentist toexactly determine in ad- Vance the proper amount of plastic materialwhich should be placed in. the tray in order to make the various shapedand sized impressions he has to make. It is perhaps safe to say thatinvariably the dentist finds that he either has too much plastic, whichresults in the above-mentioned disadvantages, or too little which meansthat he must start anew.

With the device of my invention, I not only provide means to overcomethe disadvantages of too much plastic, but I provide means whereby theamount of plastic necessary may be determined in advance. That is tosay, my device overcomes the likelihood of having too little plastic aswell.

In the drawing there is shown a tray-like member having the generalshape of the human jaw. It may be of various sizes and it is common toprovide at least three or four sizes to accommodate the jawsof averagepatients.

Preferably the tray is formed of metal but this is not essential. In anyevent, it is desirable that the tray have a side wall 2 and a centralmore or less raised part 4 with what may be called a trough part 6therebetween. The trough part 6 is for receiving the parts of the mouthfrom which the teeth ordinarily extend while the raised portion 4 isarranged to be disposed adjacent the roof of the mouth.

The central part 4 is provided with an opening I 2 of substantial sizeand this is so arranged that plastic material not needed may falltherethrough. Then hinged to the tray member as by a hinge l4, which maytake various forms, is what may be called a plate member Hi.

The plate member I6 is disposed beneath the plate member and, beinghinged at one end as shown, is movable downwardly and upwardly towardsand away from the opening l2. In this Way, excess plastic material whichhappens to be urged downwardly through the opening l2, will fall ontothe upper surface of the member l5. Preferably the member I6 is formedto have a central raised part and downwardly extending side parts, allas clearly shown in Fig. 3, so as to be more or less complemental to thetray member. That is to say, it is desirable that the plate member l6 beadapted to fit more or less snugly against the under side of the traymember so that plastic material passing through the opening I2 will fallonto the plate l6 and not intothe patients mouth. 7

In the operation of my device, the dentist takes the same, without firsthaving placed impression taking plastic in the trough thereof as isusual, and moves it upwardly against the upper jaw so that the gums aredisposed in the trough and, with the plate IS in its lowermost position(see Fig. 5) places his finger through the opening 12 so that the tip ofhis finger touches the roof of the patients mouth. Then by measuring thedistance his finger extends through the opening, the dentist mayobtainan approximate esti mate of the thickness of material needed to pro videthe proper impression.

This is to be distinguished from the present method of merely placing anunknown amount of plastic on the tray and depending more or less uponluck that enough or not too little material has been used.

According to one modification of the invention, a wad of readilycompressible material, indicated at 20 by dot-dash lines, may be causedto adhere to the plate l6. Then the tray may be placed in the patientsmouth in the manner above described with the plate IS in the positionshown in Fig. 5 and with the bottom surface of the trough 6 in properrelation to the teeth sockets. V

Whereupon the dentist may swing the plate I6 upwardly on its hinge sothat the upper part of the wad 20 engages the roof of the mouth and iscompressed downwardly a certain distance according to the height of theroof of the patients mouth. Then after removing the tray and the more orless compressed Wad 20, the dentist may by measuring the height of theplastic'determine quite accurately the amount of impressiontakingmaterial he will need.

Preferably, for convenience, the tray member has a handle 8 extendingforwardly thereof. It is usual to provide an opening [0 inthe outer endof this handle so that the dentist may hang the same on a hook or thelike, but this does not comprise an important part of this invention.

It is desired to point out that not only may the operator place thedevice in the patients mouth without impression-taking material, andthus determinethe'amount of plastic needeoL'but he may also place themore or less filled tray into the mouth Without danger of gagging, orotherwise causing discomfort to, the patient; That is -While I havedescribed the invention in great detail and with respect to a preferredform thereofgit is not desired to be limited thereto since many changesand modifications may be made therein without departing from the spiritand scope of the invention.

What it is desired to claim and secure by Letters Patent of the UnitedStates is:

As a new article of manufacture, a device of r the class describedcomprising in combination, a tray member provided with an openingtherethrough and having a trough-like part extending around a side ofsaid opening, aplate member hingedly connected to the under side of saidtray member so as to be movable between an upper position substantiallyclosing said opening and a lower position away from. said opening wherematerial on said plate member may be removed from beneath said tray, andan upstanding compressible member on the upper side of saidplate memberdisposed so as toextend through the opening in said tray member when theplate member is in its upper position.

a WILLIAM B. JONES.

